示例#1
0
文件: init.c 项目: Holong/LinuxKernel
// start_pfn : 뱅크 0 시작 주소의 물리 small page 번호		(0x20000)
// end_pfn   : 뱅크 0의 마지막 주소의 물리 small page 번호	(0x4f800)
static void __init arm_bootmem_init(unsigned long start_pfn,
	unsigned long end_pfn)
{
	struct memblock_region *reg;
	unsigned int boot_pages;
	phys_addr_t bitmap;
	pg_data_t *pgdat;
	// pg_data_t : struct pglist_data

	/*
	 * Allocate the bootmem bitmap page.  This must be in a region
	 * of memory which has already been mapped.
	 */
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	// boot_pages : 6
	// start_pfn ~ end_pfn 까지를 bitmap으로 바꿨을 때 총 프레임의 갯수가 반환됨.
	
	// boot_pages << PAGE_SHIFT : 0x6000, L1_CACHE_BYTES : 64, _pfn_to_phys(end_pfn) : 0x4F800000
	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
				__pfn_to_phys(end_pfn));
	// non-reserved 영역에서 비트맵용 영역을 만들어 가져옴
	// 영역의 시작 주소가 반환됨(물리)

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);	// 비어 있는 함수임
	pgdat = NODE_DATA(0);
	//*pgdat = contig_page_data
	//
	//	.bdata = &bootmem_node_data[0]
	//			 현재는 0으로 되어 있는 값임
	//
	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);
	// bdata_list 에 등록
	// bitmap 값을 0xFF로 초기화

	/* Free the lowmem regions from memblock into bootmem. */
	for_each_memblock(memory, reg) {
	// for (reg = memblock.memory.regions; reg < (memblock.memory.regions + memblock.memory.cnt), reg++)
		unsigned long start = memblock_region_memory_base_pfn(reg);
		unsigned long end = memblock_region_memory_end_pfn(reg);
		// start : 0x20000
		// end   : 0xA0000

		if (end >= end_pfn)
			end = end_pfn;
		if (start >= end)
			break;
		
		// start : 0x20000000, (end - start) << PAGE_SHIFT : 0x2F800000
		free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
		// start부터 end에 해당하는 bitmap을 전부 0으로 설정
		// 일단 전부 FREE로 만듬
	}
static void __init contig_initmem_init(void)
{
        unsigned long bootmap_size, bootmap; 
        bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
        bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size);
        if (bootmap == -1L) 
                panic("Cannot find bootmem map of size %ld\n",bootmap_size);
        bootmap_size = init_bootmem(bootmap >> PAGE_SHIFT, end_pfn);
        e820_bootmem_free(&contig_page_data, 0, end_pfn << PAGE_SHIFT); 
        reserve_bootmem(bootmap, bootmap_size);
} 
示例#3
0
static void __init bootmem_init_one_node(unsigned int nid)
{
	unsigned long total_pages, paddr;
	unsigned long end_pfn;
	struct pglist_data *p;

	p = NODE_DATA(nid);

	/* Nothing to do.. */
	if (!p->node_spanned_pages)
		return;

	end_pfn = p->node_start_pfn + p->node_spanned_pages;
#ifdef CONFIG_HIGHMEM
	if (end_pfn > max_low_pfn)
		end_pfn = max_low_pfn;
#endif

	total_pages = bootmem_bootmap_pages(end_pfn - p->node_start_pfn);

	paddr = memblock_alloc(total_pages << PAGE_SHIFT, PAGE_SIZE);
	if (!paddr)
		panic("Can't allocate bootmap for nid[%d]\n", nid);

	init_bootmem_node(p, paddr >> PAGE_SHIFT, p->node_start_pfn, end_pfn);

	free_bootmem_with_active_regions(nid, end_pfn);

	/*
	 * XXX Handle initial reservations for the system memory node
	 * only for the moment, we'll refactor this later for handling
	 * reservations in other nodes.
	 */
	if (nid == 0) {
		struct memblock_region *reg;

		/* Reserve the sections we're already using. */
		for_each_memblock(reserved, reg) {
			unsigned long size = reg->size;

#ifdef CONFIG_HIGHMEM
			/* ...but not highmem */
			if (PFN_DOWN(reg->base) >= highstart_pfn)
				continue;

			if (PFN_UP(reg->base + size) > highstart_pfn)
				size = (highstart_pfn - PFN_DOWN(reg->base))
				       << PAGE_SHIFT;
#endif

			reserve_bootmem(reg->base, size, BOOTMEM_DEFAULT);
		}
	}
示例#4
0
static void __init
contig_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
{
	unsigned long bootmap_size, bootmap;

	bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
	bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size);
	if (bootmap == -1L)
		panic("Cannot find bootmem map of size %ld\n",bootmap_size);
	bootmap_size = init_bootmem(bootmap >> PAGE_SHIFT, end_pfn);
	e820_bootmem_free(NODE_DATA(0), 0, end_pfn << PAGE_SHIFT);
	reserve_bootmem(bootmap, bootmap_size, BOOTMEM_DEFAULT);
} 
示例#5
0
// ARM10C 20131207
// min: 0x20000, max_low: 0x4f800
static void __init arm_bootmem_init(unsigned long start_pfn,
	unsigned long end_pfn)
{
	struct memblock_region *reg;
	unsigned int boot_pages;
	phys_addr_t bitmap;
	pg_data_t *pgdat;

	/*
	 * Allocate the bootmem bitmap page.  This must be in a region
	 * of memory which has already been mapped.
	 */
	// start_pfn: 0x20000, end_pfn: 0x4f800, end_pfn - start_pfn: 0x2f800
	// boot_pages: 0x6
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);

	// boot_pages << PAGE_SHIFT: 0x6000, L1_CACHE_BYTES: 64
	// __pfn_to_phys(0x4f800); 0x4f800000
	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
				__pfn_to_phys(end_pfn));

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);

	// pglist_data.bdata 의 bootmem_node_data 주소로 설정
	pgdat = NODE_DATA(0);

	// pgdat: ?, __phys_to_pfn(bitmap): ?, start_pfn: 0x20000, end_pfn: 0x4f800
	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

	/* Free the lowmem regions from memblock into bootmem. */
	for_each_memblock(memory, reg) {
		// start: 0x20000
		unsigned long start = memblock_region_memory_base_pfn(reg);
		// end: 0xA0000
		unsigned long end = memblock_region_memory_end_pfn(reg);

		// end: 0xA0000, end_pfn: 0x4f800
		if (end >= end_pfn)
			// end: 0x4f800
			end = end_pfn;
		// start: 0x20000, end: 0x4f800
		if (start >= end)
			break;

		// __pfn_to_phys(0x20000): 0x20000000, (end - start) << PAGE_SHIFT: 0x2f800000
		free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
	}
示例#6
0
void __init do_init_bootmem(void)
{
	unsigned long i;
	unsigned long start, bootmap_pages;
	unsigned long total_pages;
	int boot_mapsize;

	max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
	total_pages = total_lowmem >> PAGE_SHIFT;
#endif

	/*
	 * Find an area to use for the bootmem bitmap.  Calculate the size of
	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
	 * Add 1 additional page in case the address isn't page-aligned.
	 */
	bootmap_pages = bootmem_bootmap_pages(total_pages);

	start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);

	boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);

	/* Add active regions with valid PFNs */
	for (i = 0; i < lmb.memory.cnt; i++) {
		unsigned long start_pfn, end_pfn;
		start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;
		end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);
		add_active_range(0, start_pfn, end_pfn);
	}

	/* Add all physical memory to the bootmem map, mark each area
	 * present.
	 */
#ifdef CONFIG_HIGHMEM
	free_bootmem_with_active_regions(0, total_lowmem >> PAGE_SHIFT);
#else
	free_bootmem_with_active_regions(0, max_pfn);
#endif

	/* reserve the sections we're already using */
	for (i = 0; i < lmb.reserved.cnt; i++)
		reserve_bootmem(lmb.reserved.region[i].base,
				lmb_size_bytes(&lmb.reserved, i));

	/* XXX need to clip this if using highmem? */
	sparse_memory_present_with_active_regions(0);

	init_bootmem_done = 1;
}
示例#7
0
文件: mem.c 项目: 1x23/unifi-gpl
void __init do_init_bootmem(void)
{
	unsigned long i;
	unsigned long start, bootmap_pages;
	unsigned long total_pages;
	int boot_mapsize;

	max_pfn = total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;
#ifdef CONFIG_HIGHMEM
	total_pages = total_lowmem >> PAGE_SHIFT;
#endif

	/*
	 * Find an area to use for the bootmem bitmap.  Calculate the size of
	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
	 * Add 1 additional page in case the address isn't page-aligned.
	 */
	bootmap_pages = bootmem_bootmap_pages(total_pages);

	start = lmb_alloc(bootmap_pages << PAGE_SHIFT, PAGE_SIZE);
	BUG_ON(!start);

	boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);

	/* Add all physical memory to the bootmem map, mark each area
	 * present.
	 */
	for (i = 0; i < lmb.memory.cnt; i++) {
		unsigned long base = lmb.memory.region[i].base;
		unsigned long size = lmb_size_bytes(&lmb.memory, i);
#ifdef CONFIG_HIGHMEM
		if (base >= total_lowmem)
			continue;
		if (base + size > total_lowmem)
			size = total_lowmem - base;
#endif
		free_bootmem(base, size);
	}

	/* reserve the sections we're already using */
	for (i = 0; i < lmb.reserved.cnt; i++)
		reserve_bootmem(lmb.reserved.region[i].base,
				lmb_size_bytes(&lmb.reserved, i));

	/* XXX need to clip this if using highmem? */
	for (i = 0; i < lmb.memory.cnt; i++)
		memory_present(0, lmb_start_pfn(&lmb.memory, i),
			       lmb_end_pfn(&lmb.memory, i));
	init_bootmem_done = 1;
}
示例#8
0
void __init setup_bootmem_node(int nid, unsigned long start, unsigned long end)
{
    unsigned long bootmap_pages;
    unsigned long start_pfn, end_pfn;
    unsigned long bootmem_paddr;

    /* Don't allow bogus node assignment */
    BUG_ON(nid > MAX_NUMNODES || nid <= 0);

    start_pfn = start >> PAGE_SHIFT;
    end_pfn = end >> PAGE_SHIFT;

    pmb_bolt_mapping((unsigned long)__va(start), start, end - start,
                     PAGE_KERNEL);

    lmb_add(start, end - start);

    __add_active_range(nid, start_pfn, end_pfn);

    /* Node-local pgdat */
    NODE_DATA(nid) = __va(lmb_alloc_base(sizeof(struct pglist_data),
                                         SMP_CACHE_BYTES, end));
    memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));

    NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
    NODE_DATA(nid)->node_start_pfn = start_pfn;
    NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;

    /* Node-local bootmap */
    bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
    bootmem_paddr = lmb_alloc_base(bootmap_pages << PAGE_SHIFT,
                                   PAGE_SIZE, end);
    init_bootmem_node(NODE_DATA(nid), bootmem_paddr >> PAGE_SHIFT,
                      start_pfn, end_pfn);

    free_bootmem_with_active_regions(nid, end_pfn);

    /* Reserve the pgdat and bootmap space with the bootmem allocator */
    reserve_bootmem_node(NODE_DATA(nid), start_pfn << PAGE_SHIFT,
                         sizeof(struct pglist_data), BOOTMEM_DEFAULT);
    reserve_bootmem_node(NODE_DATA(nid), bootmem_paddr,
                         bootmap_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);

    /* It's up */
    node_set_online(nid);

    /* Kick sparsemem */
    sparse_memory_present_with_active_regions(nid);
}
示例#9
0
文件: setup.c 项目: jamesyc/kitten
/**
 * This sets up the bootstrap memory allocator.  It is a simple
 * bitmap based allocator that tracks memory at a page granularity.
 * Once the bootstrap process is complete, each unallocated page
 * is added to the real memory allocator's free pool.  Memory allocated
 * during bootstrap remains allocated forever, unless explicitly
 * freed before turning things over to the real memory allocator.
 */
static void __init
setup_bootmem_allocator(
	unsigned long	start_pfn,
	unsigned long	end_pfn
)
{
	unsigned long bootmap_size, bootmap;

	bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
	bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size, PAGE_SIZE);
	if (bootmap == -1L)
		panic("Cannot find bootmem map of size %ld\n",bootmap_size);
	bootmap_size = init_bootmem(bootmap >> PAGE_SHIFT, end_pfn);
	e820_bootmem_free(0, end_pfn << PAGE_SHIFT);
	reserve_bootmem(bootmap, bootmap_size);
}
示例#10
0
void __init setup_bootmem_node(int nid, unsigned long start, unsigned long end)
{
	unsigned long bootmap_pages, bootmap_start, bootmap_size;
	unsigned long start_pfn, free_pfn, end_pfn;

	/* Don't allow bogus node assignment */
	BUG_ON(nid > MAX_NUMNODES || nid == 0);

	/*
	 * The free pfn starts at the beginning of the range, and is
	 * advanced as necessary for pgdat and node map allocations.
	 */
	free_pfn = start_pfn = start >> PAGE_SHIFT;
	end_pfn = end >> PAGE_SHIFT;

	__add_active_range(nid, start_pfn, end_pfn);

	/* Node-local pgdat */
	NODE_DATA(nid) = pfn_to_kaddr(free_pfn);
	free_pfn += PFN_UP(sizeof(struct pglist_data));
	memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));

	NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
	NODE_DATA(nid)->node_start_pfn = start_pfn;
	NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;

	/* Node-local bootmap */
	bootmap_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	bootmap_start = (unsigned long)pfn_to_kaddr(free_pfn);
	bootmap_size = init_bootmem_node(NODE_DATA(nid), free_pfn, start_pfn,
				    end_pfn);

	free_bootmem_with_active_regions(nid, end_pfn);

	/* Reserve the pgdat and bootmap space with the bootmem allocator */
	reserve_bootmem_node(NODE_DATA(nid), start_pfn << PAGE_SHIFT,
			     sizeof(struct pglist_data), BOOTMEM_DEFAULT);
	reserve_bootmem_node(NODE_DATA(nid), free_pfn << PAGE_SHIFT,
			     bootmap_pages << PAGE_SHIFT, BOOTMEM_DEFAULT);

	/* It's up */
	node_set_online(nid);

	/* Kick sparsemem */
	sparse_memory_present_with_active_regions(nid);
}
示例#11
0
static void __init
contig_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
{
	unsigned long bootmap_size, bootmap;

	bootmap_size = bootmem_bootmap_pages(end_pfn)<<PAGE_SHIFT;
	bootmap = find_e820_area(0, end_pfn<<PAGE_SHIFT, bootmap_size);
	if (bootmap == -1L)
		panic("Cannot find bootmem map of size %ld\n",bootmap_size);
	bootmap_size = init_bootmem(bootmap >> PAGE_SHIFT, end_pfn);
#ifdef CONFIG_XEN
	e820_bootmem_free(NODE_DATA(0), 0, xen_start_info->nr_pages<<PAGE_SHIFT);
#else
	e820_bootmem_free(NODE_DATA(0), 0, end_pfn << PAGE_SHIFT);
#endif
	reserve_bootmem(bootmap, bootmap_size);
} 
示例#12
0
文件: init.c 项目: AshishPrasad/BTP
static void __init arm_bootmem_init(struct meminfo *mi,
	unsigned long start_pfn, unsigned long end_pfn)
{
	unsigned int boot_pages;
	phys_addr_t bitmap;
	pg_data_t *pgdat;
	int i;

	/*
	 * Allocate the bootmem bitmap page.  This must be in a region
	 * of memory which has already been mapped.
	 */
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
				__pfn_to_phys(end_pfn));

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);
	pgdat = NODE_DATA(0);
	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

	for_each_bank(i, mi) {
		struct membank *bank = &mi->bank[i];
		if (!bank->highmem)
			free_bootmem(bank_phys_start(bank), bank_phys_size(bank));
	}

	/*
	 * Reserve the memblock reserved regions in bootmem.
	 */
	for (i = 0; i < memblock.reserved.cnt; i++) {
		phys_addr_t start = memblock_start_pfn(&memblock.reserved, i);
		if (start >= start_pfn &&
		    memblock_end_pfn(&memblock.reserved, i) <= end_pfn)
			reserve_bootmem_node(pgdat, __pfn_to_phys(start),
				memblock_size_bytes(&memblock.reserved, i),
				BOOTMEM_DEFAULT);
	}
}
示例#13
0
static void __init bootmem_init_one_node(unsigned int nid)
{
	unsigned long total_pages, paddr;
	unsigned long end_pfn;
	struct pglist_data *p;

	p = NODE_DATA(nid);

	/* Nothing to do.. */
	if (!p->node_spanned_pages)
		return;

	end_pfn = p->node_start_pfn + p->node_spanned_pages;

	total_pages = bootmem_bootmap_pages(p->node_spanned_pages);

	paddr = memblock_alloc(total_pages << PAGE_SHIFT, PAGE_SIZE);
	if (!paddr)
		panic("Can't allocate bootmap for nid[%d]\n", nid);

	init_bootmem_node(p, paddr >> PAGE_SHIFT, p->node_start_pfn, end_pfn);

	free_bootmem_with_active_regions(nid, end_pfn);

	/*
	 * XXX Handle initial reservations for the system memory node
	 * only for the moment, we'll refactor this later for handling
	 * reservations in other nodes.
	 */
	if (nid == 0) {
		struct memblock_region *reg;

		/* Reserve the sections we're already using. */
		for_each_memblock(reserved, reg) {
			reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
		}
	}
示例#14
0
static void __init arm_bootmem_init(unsigned long start_pfn,
	unsigned long end_pfn)
{
	struct memblock_region *reg;
	unsigned int boot_pages;
	phys_addr_t bitmap;
	pg_data_t *pgdat;

	/*
	 * Allocate the bootmem bitmap page.  This must be in a region
	 * of memory which has already been mapped.
	 */
	boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
	bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
				__pfn_to_phys(end_pfn));

	/*
	 * Initialise the bootmem allocator, handing the
	 * memory banks over to bootmem.
	 */
	node_set_online(0);
	pgdat = NODE_DATA(0);
	init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

	/* Free the lowmem regions from memblock into bootmem. */
	for_each_memblock(memory, reg) {
		unsigned long start = memblock_region_memory_base_pfn(reg);
		unsigned long end = memblock_region_memory_end_pfn(reg);

		if (end >= end_pfn)
			end = end_pfn;
		if (start >= end)
			break;

		free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
	}
示例#15
0
文件: setup.c 项目: ANFS/ANFS-kernel
static void __init
setup_memory(void)
{
        unsigned long bootmap_size;
	unsigned long start_pfn, end_pfn;
	int i;

	/*
	 * partially used pages are not usable - thus
	 * we are rounding upwards:
	 */
	start_pfn = PFN_UP(__pa(&_end));
	end_pfn = max_pfn = PFN_DOWN(memory_end);

#ifdef CONFIG_BLK_DEV_INITRD
	/*
	 * Move the initrd in case the bitmap of the bootmem allocater
	 * would overwrite it.
	 */

	if (INITRD_START && INITRD_SIZE) {
		unsigned long bmap_size;
		unsigned long start;

		bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
		bmap_size = PFN_PHYS(bmap_size);

		if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
			start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;

			if (start + INITRD_SIZE > memory_end) {
				pr_err("initrd extends beyond end of "
				       "memory (0x%08lx > 0x%08lx) "
				       "disabling initrd\n",
				       start + INITRD_SIZE, memory_end);
				INITRD_START = INITRD_SIZE = 0;
			} else {
				pr_info("Moving initrd (0x%08lx -> "
					"0x%08lx, size: %ld)\n",
					INITRD_START, start, INITRD_SIZE);
				memmove((void *) start, (void *) INITRD_START,
					INITRD_SIZE);
				INITRD_START = start;
			}
		}
	}
#endif

	/*
	 * Initialize the boot-time allocator
	 */
	bootmap_size = init_bootmem(start_pfn, end_pfn);

	/*
	 * Register RAM areas with the bootmem allocator.
	 */

	for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
		unsigned long start_chunk, end_chunk, pfn;

		if (memory_chunk[i].type != CHUNK_READ_WRITE)
			continue;
		start_chunk = PFN_DOWN(memory_chunk[i].addr);
		end_chunk = start_chunk + PFN_DOWN(memory_chunk[i].size);
		end_chunk = min(end_chunk, end_pfn);
		if (start_chunk >= end_chunk)
			continue;
		add_active_range(0, start_chunk, end_chunk);
		pfn = max(start_chunk, start_pfn);
		for (; pfn < end_chunk; pfn++)
			page_set_storage_key(PFN_PHYS(pfn),
					     PAGE_DEFAULT_KEY, 0);
	}

	psw_set_key(PAGE_DEFAULT_KEY);

	free_bootmem_with_active_regions(0, max_pfn);

	/*
	 * Reserve memory used for lowcore/command line/kernel image.
	 */
	reserve_bootmem(0, (unsigned long)_ehead, BOOTMEM_DEFAULT);
	reserve_bootmem((unsigned long)_stext,
			PFN_PHYS(start_pfn) - (unsigned long)_stext,
			BOOTMEM_DEFAULT);
	/*
	 * Reserve the bootmem bitmap itself as well. We do this in two
	 * steps (first step was init_bootmem()) because this catches
	 * the (very unlikely) case of us accidentally initializing the
	 * bootmem allocator with an invalid RAM area.
	 */
	reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
			BOOTMEM_DEFAULT);

#ifdef CONFIG_BLK_DEV_INITRD
	if (INITRD_START && INITRD_SIZE) {
		if (INITRD_START + INITRD_SIZE <= memory_end) {
			reserve_bootmem(INITRD_START, INITRD_SIZE,
					BOOTMEM_DEFAULT);
			initrd_start = INITRD_START;
			initrd_end = initrd_start + INITRD_SIZE;
		} else {
			pr_err("initrd extends beyond end of "
			       "memory (0x%08lx > 0x%08lx) "
			       "disabling initrd\n",
			       initrd_start + INITRD_SIZE, memory_end);
			initrd_start = initrd_end = 0;
		}
	}
#endif
}